194 HENDEESON'S HANDBOOK OF PLANTS HOB the Horseradish nearer, so that when grown between Beets It should be planted at the dis¬ tance of two feet between the plants in the rows, making about the same number of plants per acre as when planted between Early Cabbages. This manner of growing Horseradish we claim to be a great advance on the methods generaUy practised. AU American writers on the subject, that we have seen, loUow in the same track, and recommend planting the crowns. This not only destroys the most sale¬ able part ol the root, but when planted thus, the crowns produce only a sprawling lot ol rootlets which are utterly unsaleable in the market. Horseradish Tree. See Moringa. Horse-tail. The genus Equiaetum. Hortensis. 01 or belonging to a garden; the word is olten contracted thus: hort. Hotei'a Japonica. A synonym ol Spiraea or Astilbe Japonica. Hottentot Bread. A South Alrican name lor Testudinaria Elephantipes. Hottentot Fig. Meaembryanthemum edule. Hotto'aia. Water Violet. Named alter P. Hotton, a Duteh botanist. Nat. Ord. Primu¬ lacem. Hardy aquatic or marsh plants. H. injkda is common in pools and ditches Irom New England southward. H. palustria, the Water Violet, is a singular and beautilul plant, com¬ mon In pools in many parts ot England. The leaves grow wholly under water; Irom them there arises a long fiower stalk bearing a pyramid ol blue or white flowers, which are disposed In whorls. It is a very interesting plant lor the aquarium. HpuUe'tia. Named alter M. Houllet, a French gardener. Nat. Ord. Orchidacem. A small genus ol very handsome epiphytal Orchids, natives ol BrazU. The genus Is re¬ lated to Stanhopea, and requires the same treatment. Hound's Tongue. See Cynogloaaum. Houseleek. See Sempervivum. Housto'nia. Named In honor ot Dr. W. Houston, an English botanist. Nat. Ord. Rubiacem. This elegant genus ol small flowering plants Is found throughout the Northern and Western States. They are weU adapted lor flower borders, "rock-work, or shaded beds, and thrive best in a moist situation. The colors ol the flowers are white, blue and pur¬ ple. Herbaceous perennials, popularly known as Bluets, and propagated by division ol the roots. Ho'vea. Named alter A. P. Hove, a Polish botanist. Nat. Ord. Leguminoam. A genus ol handsome, blue-flowered ever¬ green shrubs Irom New Holland. " H CelaU (Syn. H elliptica), one ol the best known, is a beautilul green-house plant, flowering like most ol the species, in the spring. This plant exhibits the peculiarity ol the flower buds ol the preceding year appearing at the base ol those expanded during the present; a common condition ol leal buds, which are always visi¬ ble the season preceding their expansion, but not Irequently so with flower buds, which, though they may be lormed several years HUG before their development extemally, gener¬ ally remain concealed till the period ol their unfolding." The flowers are pea-shaped, ax¬ illary, on short peduncles. Propagated by seeds; Introduced In 1818. Hove'nia. In honor of David Hoven, a Senator of Amsterdam, who contributed to the success of the travels of Thunberg. Nat. Ord. Rhamncuiem. These are small fruit-bearing trees, growing to the height of eight or ten feet, and pro¬ ducing a fruit which is said to taste Uke the Bergamot pear. H. dulda, a native of Japan, has been Introduced into this country, and grown as an ornamental fruit-bearing tree. None of the other species are hardy. Ho'wea. From Lord Howe's Island where only the genus is found. Nat. Ord. Palmacem. This name is now generally adopted for the two palms introduced and cultivated under the names of Kentia Belmoreana, and K. Poateriana. Ho'ya. Wax Flower. In honor of Thomas Hoy, P. L. S., gardener to the Duke of Northumber¬ land at Slon House, England. Nat. Ord. AacUpiadaeeoB. The most common species, H. Camosa, has curious, wax-like flowers, from which drops a sweet, honey-like juice. It is a hot-house cUmber, which requires a light rich soil, and is propagated by cuttings, which require an average temperature ol not less than 75° to root Ireely. It is sometimes grown in green¬ houses, in a warm situation, exposed to the sun. It makes an excellent plant lor a warm sitting-room, as it grows Ireely without direct light. Introduced Irom Asia in 1802. The variegated-leaved variety is a very orna- mental plant; H. bella, with beautilul waxy white flowers and dwart shrubby slender habit, forms an excellent subject for a hang¬ ing basket in a warm green-house. There are many other species ol much beauty, all requir¬ ing a warm plant-stove to bring them to per¬ fection. Huckleberry. 'Whortleberry. The popular names ol the genus Oayhissada, ol which there are several species. G. dumoaa, the Dwarl Huckleberiy, G. frondoaa, the Blue Huckleberry, and G. resinosa, the Black Huckleberry, are common throughout the United States, the latter being the Huckle¬ berry ol the Northern States. Hudso'nia. False Heath. Named alter William Hudson, author ol "Flora Anglica." Nat. Ord. Cistacem. A genus ot bushy Uttle heath-like shrubs, seldom a loot high, covered all over with small awl-shaped or scale-like persistent downy leaves, and bearing numerous small, but showy yellow flowers in May, crowded along the upper part ol the branches. Found in dry sandy soil near the coast, from Maine to\irginia. From its resemblance when not in bloom to Heather {Galluna vulgaris), it Is often taken lor that plant. Huge'Ua. Named alter Baron Hugel, ol Vienna, Nat. Ord. Polemoniacem. A small genus ol hardy annuals Irom Cali¬ fomia with blue and yellow flowers, propagated by seeds. First discovered in 1833. This genus Is now Included under Gilia.